Steam-turbine installation



Feb. 23 192s. 1,573,851

H. NYFFENEGGER STEAM TURBINE INSTALLATION Filed April 29 1935 PatentedFeb. 23, 1926.

IUNIT'ED STATES- PATEN HANS NYFFENEGGER, 10F ZURICH, SWITZERLAND,ASSIGNOR TO THE FIRM OF AKTIENGESELLSCHAFT DER MASCHINENFABRIKEN ESGHERWYSS & CIE., OF

ZURICH, SWITZERLAND.

STEAM-TURBINE IN STALLATIOIV.

Application filed April 29, '1925. Serial No; 26,706.

'To all whom it may concern ,"Be it known that I, HANS NYFFnNueeniz, acitizen of the SWiss'Republic, residing at Zurich, Switzerland, haveinvented an Improvement in Steam-Turbine Installations,

of which the following description, in c011 nection with theaccompanying drawings, is a specification, like characters on thedrawings representing like parts. i

This invention relates to improvements in steam-turbine installations inwhich a preheating of the feed-water in several steps is effected bymeans of bleeder steam.

It is a known fact that the step by step preheating of the feed-water bymeans of steam tapped from different stages of a turbine of a steampower installation involves an increased economy of the installation, asthe tapped steam after having performed mechanical work, delivers thegreater part of its evaporation heat to the feedwater, so

that its latent heat is recovered. The tapping of steam from a turbinerequires however a turbine casing of a special design, and the initialcost of the latter is therefore considerably raised if steam has to betapped from several stages. A further disadvantage of tappings atseveral places, particularly with transversely arranged turbines onlocomotives, is that it increases the axial length of the'turbine, sothat owing to the limitations imposed by the railway clearance gauge,such a turbine could in many cases not be employed on locomotives.

According to the present invention, the tapping ofthe steam required forpreheat ing the feed-water is effected at one single place only. Thissteam flows in'conduits which are arranged in parallel to the differentstages of the feed-Water heater and in these conduits appliancesutilizing different heat drops are interposed at least in those conduitswhich lead the 'bleeder steam to the initial and subsequentpreheaterstages up to the secondlast stage.

The application of the invention to installations having a turbine withmore than one casing and a reheater interposed-between two such turbinecasings affords besides a simplification'of the design'of the turbinecasings thermodynamical advantages if the tapping is made from theconnection joining thefirst turbine casing to the intermediatere-heater. In this casethe intermediate reheatcr is substantiallyrelieved and too highly superheated steam does not fiow to the preheaterstages, as would otherwise occur when multiple tappings are.en 1- ployedand in which case the tapped steam cannot then be fully utilized in thestages of the preheater since the saturation temperature determines thelimit to which preheating can be effected.

Illustrations of the subject matter of the present invention are givenon the accompanying drawings in which:

Fig. 1 shows a steam-turbine installation, in which the steam forheating the preheaters is bled from one point of the main turbine,

Fig. 2 shows a twin casing steam-turbine installation, in which thesteam for heating purposes is bled from a two casings,

Figs. 3 and at show detail modifications.

In the installation illustrated in Fig. 1, 1 denotes the boiler,2 asuperheater and 3 the main turbine of the installation. A branch (3 isprovided for extracting the steam for heating purposes requiredin afeed-water heater 7- having three stages.

Thetapped steam flows to the three stages point between the thecondenser 13 via the conduit 16 and delivering it into the feed-waterheater 7 from which the preheated feed-water. flows through the conduit15 into the boiler 1.

lVith the above described installation of the tapping of, the steamutilized for preheating purposes in the various stages of the prehcater7 occurs at the single place 6. Fig.- 2 shows an installation in whichthe main turbine is designed asa twin-casing turbine; 3 is thehigh-pressure part and *l: the low-pressure part. 2 is again asuperheater and 5 denotes an intermediate re; heater placed between thehigh pressure part 3 and the low pressure part 4. The

steam for heating purposes is tap 38d from a point 6', situated betweenthe high pressure part 3 and the re-heater 5. In other respects thisinstallation is identical to that described above; v

The connection branch for bleeding the -steam can be situated at anysuitable point on the main turbine whether single or multiple casingsare employed. When .the main turbine is designed with a multi-casing,the

point of tapping may be arranged at the ex;

aust trunk of one of the turbine casings as is indicated at 17 in Fig.3. p

Instead of theauxiliary turbines 11 and 12, obviously other appliancesrequiring heat such as steam engines, steam hammers, installations forevaporating and heating -'purposes,.may be inserted in the conduits 8and 9 arranged in parallel. The number of the-conduits arranged inparallel and of the stages of the feed-water heater does not in- 3fiuence the scope of the invention. Further several stages and adaptedto-be heated by steam-tapped at a single point on the turbineinstallation, conduits arranged in parallel and leading said tappedsteam to the stages of said feed-water heater, and apgliances requiringheat adapted to utilize ifierent heat drops and interposed at least inthose of said conduits which lead the bleeder steam to the initial andsubsequent preheater stages up to the second last stage.

2. A steam-turbine installation, including in'combination a feed-waterheater having several stages, means to tap steam fromsaid turbineinstallation at one point only, conduits arranged in parallel andleading said tapped steam to the stages of said feed-water heater, andappliances requiring heat oper- 'ating under difierent heat drops andinsertedin said conduits. 3. A steam-turbine installation, including inCOIIlblllLtlOll, a multi-casing turbine, a

feed-water heater having several stages, an

intermediate re-heater situated "between two of the turblne casin s,meansto tap' steam at a point in front 0 the re-heater, conduitsarranged in parallel and leading said tapped steam to the stages of saidfeed-water heater, and appliances requiring heat operating underdifi'erent heat'drops and inserted in said conduits.

4. A steam-turbine installation, including in combination afeed-waterheater having several stages, means to tap steam from said turbineinstallation at one point only, conduits arranged in parallel andleading said tapped steam to the stages of said feed-water heater, andsteam power engines operating with different expansion ratios insertedin said conduits. V

'5. A steam-turbine installation, including in combination a mainturbine, a feed-water h eater having several stages,- means to tap steamfrom said main turbine at one point 0nly,'conduits arranged in aralleland leading said tapped steam to t e stages of said feed-water heater,and steam turbines operating with different expansion ratios inserted insaid conduits.

'6. A steam-turbine, installation, including in. combination amulti-casing turbine,

a feed-Water heater having several stages,

an intermediate re-heater interposed between two of the casings of theturbine, means to tap steam from said turbine installation at a point infront of the reheater, conduits arranged in parallel and leading saidtapped steam to the stages of said feed-waterheater, and steam turbznesoperating with different expansion ratios inserted in said conduits. Intestimony whereof, I have name to this specification.

HANS NYFFENEGGER;"/

si n y

